Mold for casting piano-plates.



H. R. SIMMS.

MOLD FOR CASTING PIANO PLATES. APPLICATION FILED JAN-15.1915. 1,181,178. Patented May 2,1916.

WITNESSES.-

'NVEN TOR.

H. R. SIMMS.

MOLD FOR CASTING PIANO PLATES.

APPLICATION FILED JAN. 15,1915.

1, 1 8 1 9 l 78 Patented May 2, 1916.

2 SHEETS-SHEET 2- ATTORNEYS AFN FFIC.

HORACE R. SIMMS, 0F RACINE, WISCONSIN. ASSIGNOR T0 AMERICAN SKEIN & FOUNDRY COMPANY, OF RACINE, WISCONSIN, A CORPORATION OF WISCONSIN.

MOLD FOR CASTING PIANO-PLATES.

Specification of Letters Patent.

Patented May 2, 1916.

Original application filed September 28, 1914, Serial No. 863,964. Divided and this application filed January To all whom it may concern.-

Be it known that I, HORACE R. SIMMs, a citizen of the United States, residing at Racine, in the county of Racine and State of Wisconsin, have invented certain new and useful Improvements in Holds for Casting Piano-Plates, of which the following is a specification.

My invention relates to the manufacture of piano plates, and particularly to the provision of the plates with pins or studs for the piano strings which are united with the plates during the casting operation.

The present application is a division of my co-pending application Serial No. 863,964, filed September 28, 1914.. This application, as filed, described and claimed a method of and apparatus for making a mold for casting piano plates and uniting the pins or studs therewith during the casting operation and claimed also, as an article of manufacture, the mold produced by said method. The claims on the mold were subsequently withdrawn in compliance with a requirement for division.

In the manufacture of piano plates it was formerly the practice to provide the plates with studs for the piano strings after the plates had been cast, that is, holes were drilled in the casting and the pins driven into or otherwise fixed in the holes. This method was a tedious and expensive one and to avoid its disadvantages efforts were made to cast the pins into the plate. This operation, however, is attended with considerable difiiculty. There are quite a large number of pins on each plate. The pins are comparatively small, projecting but a short distance above the rib of the casting with which they are united, and are arranged close together. It is essential that they be accurately spaced one from the other and firmly united to the plate. Under such circumstances it is obviously impractical to afiix the pins in the mold after the latter has been formed. If the pins are inserted in holes in the pattern the removal of the pattern is likely to pull out the pins or disturb them from their intended position in the sand of the mold. The expedient has been tried of providing longitudinal supports for the pins during the withdrawal of the pattern. This method, however, is open to the objection that it is very difficult- Serial No. 2,400.

to prevent the supporting devices from being shifted laterally during the withdrawal of the pattern and any such shifting movement is likely to loosen the pins in the sand of the mold.

The method which I have devised consists in arranging the pins in proper spaced relation with each other in a dry or baked sand core in which the ends of the pins are fixed, and embedding the core thus formed in the greensand making up the body of the mold with the free ends of the pins projecting into the mold cavity so that the metal will flow around them when the casting is made. By this expedient there is no dangerthat the withdrawal of the pattern will disturb the pins from their position in the mold. Furthermore, the fact that the ends of the pins are embedded in and firmly ad here to the core which is itself embedded up to its upper surface in the sand of the mold, prevents the accidental displacement of the pins in handling the mold after the pattern is withdrawn.

In the accompanying drawings Figure 1 is a view, in perspective, of a piano plate manufactured in accordance with my invention. Fig. 2 is a plan view of the lower element of the mold for casting a plate such as that shown in Fig. 1. Figs. 3, 4 and 5 are sectional views taken on lines 3-3, 4-4 and 55 of Fig. 2, but showing the upper mold element in place on the lower element. Fig. 6 is a view, in perspective, of one of the dry sand cores provided with a double row of pins. Fig. 7 is a similar view of a dry sand core having a single row of pins; and Fig. 8 is a fragmentary View, in perspective, of the core box for making the core shown in Fig. 6, the finished core with the pins united thereto being shown in the core box.

Like characters of reference designate like parts in the several figures of the drawings.

As will be seen by reference to Fig. l, the piano plate consists of a skeleton frame 10 comprising a web 11 to which are afiixed, in the particular type of plate shown, a single row of pins 12 and further on a double row of pins 13.

In making a mold for casting a plate of this character the pins 12, 13 are aiiixed in proper spaced relation to a dry sand core preferably made in a plurality of sections.

I have indicated the core as consisting of three sections 16, 17 and 18, but the number, of course, is unimportant. The ends of the pins, designed to project up from the piano plate, are embedded in the core sections. This is preferably accomplished in the manner indicated in Fig. 8 which shows a core box for forming the core section 16 having the double row of pins. The core box consists of three separable parts 19, 20, 21, and is formed with perforations 22 at the meet ing edges of the parts of the box. The core box is placed upon a table with its perforated side downward and the pins are put in place in the perforations with their lower ends resting on the table. The box is then filled with any material suitable for making what are known as dry sand cores. When the core has been molded in this manner the core box is turned over to the position shown in Fig. 8 and is removed from the core in sections. In this way there is no danger of disturbing the pins which have been accurately positioned in the core by means of the perforations 22. The core is then baked in the usual manner, which hardens it and caused the pins to firmly adhere thereto. The core sections 17 and 18, having the single row of pins, may be made in the same manner, the core box, in each case, consisting of two pieces and being formed with a single row of perforations.

Assuming that the mold is made in a molding machine in which the pattern is lowered from the flask after the sand has been rammed, the core sections, made as above described, are placed on the pattern with the projecting ends of the pins extending downwardly through suitably formed apertures in the pattern. The green sand is then rammed around the pattern and core sections and when this has been accomplished the pattern is withdrawn, leaving the core sections embedded in the green sand of the mold with the ends of the pins projecting into the portion 23 of the'mold cavity which forms rib 11 of the casting.

In Figs. 3 to 5 inclusive, 24L designates the drag and 25 the body of green sand in which the core sections 16, 17 and 18 are embedded as above described. 26 designates the cope and 27 the body ofgreen sand therein which 28. Preferably the core sections 16, 17 and 18 are wider at the bottom than at the top so that there is no danger that they will fall or be drawn out of the green sand when the pattern is lowered.

By the expedient of first embedding the pins in accurately spaced relation in a dry sand core and then embedding the dry sand core in'the green sand constituting the body.

of the mold, it is possible to position the pins in the finished casting with the utmost accuracy and precision. Furthermore, there is no danger that any of the pins should become dislodged or moved out of alinement either when the pattern is withdrawn or subsequently in the handling of the mold. The core sections will be exactly alike for successive molds since they are made in the same core boxes. The piano plates will, therefore, be precisely uniform in respect to the disposition of the pins. The molds for successive plates may be produced very quickly and at relatively small expense.

I claim:

1. A mold for casting piano plates and uniting with said plates, during the casting operation, pins for the piano strings, comprising a body of green sand and embedded in the same, with one face exposed, a dry sand core; said pins being fixed in proper spaced relation to the exposed face of the dry sand core with one end, in each case, embedded in and firmly adhering to the material of the core and the other projecting into the mold cavity.

2. A mold for casting piano plates and uniting with said plates, during the casting operation, pins for the piano strings, comprising a body of green sand and embedded in the same, with one face exposed, a dry sand core which is wider across its inner face than at the exposed surface so that said core is anchored in the green sand of the mold; said pins being fixed in proper spaced relation to the exposed face of the dry sand core with one end, in each case, embedded.

in and firmly adhering to the material of the core and the other projecting into the mold cavity.

HORACE R. SIMMS.

Vitnesses VALTER F. WALKER, P. H. TRUMAN.

Copies. '0! this patent may be obtained for five cents each, by addressing the Commissioner 0! Patents,

Washington, D. C. 

